drm/i915/gem/i915_gem_ttm_move: Provide a couple of missing descriptions for 'num_pages' and 'ctx'

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c:272: warning: Function parameter or member 'num_pages' not described in 'i915_ttm_memcpy_arg'
 drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c:569: warning: Function parameter or member 'ctx' not described in 'i915_ttm_move'

Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230331092607.700644-12-lee@kernel.org

drivers/gpu/drm/i915/gem/i915_gem_ttm_move.c

@@ -237,6 +237,7 @@ static struct dma_fence *i915_ttm_accel_move(struct ttm_buffer_object *bo,
  * @_src_iter: Storage space for the source kmap iterator.
  * @dst_iter: Pointer to the destination kmap iterator.
  * @src_iter: Pointer to the source kmap iterator.
+ * @num_pages: Number of pages
  * @clear: Whether to clear instead of copy.
  * @src_rsgt: Refcounted scatter-gather list of source memory.
  * @dst_rsgt: Refcounted scatter-gather list of destination memory.
@@ -541,6 +542,8 @@ __i915_ttm_move(struct ttm_buffer_object *bo,
  * i915_ttm_move - The TTM move callback used by i915.
  * @bo: The buffer object.
  * @evict: Whether this is an eviction.
+ * @ctx: Pointer to a struct ttm_operation_ctx indicating how the waits should be
+ *       performed if waiting
  * @dst_mem: The destination ttm resource.
  * @hop: If we need multihop, what temporary memory type to move to.
  *